Q. The speed of body moving with uniform acceleration is $u.$This speed is doubled while covering distance $S$, its speed would be become
A) $\sqrt{3}u$
B) $\sqrt{5}u$
C) $\sqrt{11}u$
D) $\sqrt{7}u$
Explanation
(d) As $v^{2} = u^{2} + 2as \Rightarrow (2y)^{2} = u^{2} + 2as \Rightarrow = 3u^{2}$
Now, after covering an additional distance $s$, if velocity becomes $v$,then,
$v^{2} = u^{2} + 2a(2s) = u^{2} + 4as = u^{2} + 6u^{2} = 7u^{2}$
$\therefore v = \sqrt{7}u$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.